Anode catalyst materials for use in fuel cells

Abstract

Catalyst materials having a surface comprising a composition Mx/Pty/Sub; wherein M is selected from the group of elements Fe, Co, Rh and Ir; or wherein M represents two different elements selected from the group comprising Fe, Co, Rh, Ir, Ni, Pd, Cu, Ag, Au and Sn; and wherein Sub represents a substrate material selected from Ru and Os; the respective components being present within specific ranges, display improved properties for use in anodes for low-temperature fuel cell anodes for PEMFC fuel cells and direct methanol fuel cells.

What is claimed is:  
     
       1. A CO tolerant low temperature fuel cell anode catalyst material having a surface, comprising: 
       a composition M x /Pt y /Sub;  
       wherein M is selected from the group consisting of elements Fe, Co, Rh and Ir; or  
       M represents M 1   m +M 2   n ;  
       M 1  and M 2  are different from each other, and are selected from the group of elements consisting of Fe, Co, Rh, Ir, Ni, Pd, Cu, Ag, Au and Sn;  
       Sub represents a substrate metal selected from the group consisting of Ru and Os; wherein said substrate metal may be present at the surface of an anode material in an amount of less than 25%; and wherein said substrate metal is alloyed in the bulk with the metal M and Pt;  
       x is a number in the range of 0.7 to 1.3;  
       y is a number in the range of 0.7 to 2.3;  
       m and n are each a number in the range of 0.7 to 2.3; and  
       x, y, m and n signify the relative occurrence of the different elements at the surface, not including the substrate metal.  
     
     
       2. The material of  claim 1 , wherein M is selected from the group consisting of Fe, Co, Rh and Ir. 
     
     
       3. The material of  claim 2 , wherein M is Fe. 
     
     
       4. The material of  claim 2 , wherein M is Co. 
     
     
       5. The material of  claim 2 , wherein M is Rh. 
     
     
       6. The material of  claim 2 , wherein M is Ir. 
     
     
       7. The material of  claim 1 , wherein M 1  and M 2  represent Co and Fe, respectively. 
     
     
       8. The material of  claim 1 , wherein M 1  and M 2  represent Ni and Fe, respectively. 
     
     
       9. The material of  claim 3 , wherein the composition is Fe/Pt 2 /Ru. 
     
     
       10. The material of  claim 7 , wherein the composition is Co/Fe/Pt/Ru. 
     
     
       11. The material of  claim 8 , wherein the composition is Ni/Fe/Pt/Ru. 
     
     
       12. An anode for a fuel cell, comprising: 
       the catalyst material according to  claim 1 .  
     
     
       13. A fuel cell comprising: 
       the anode according to  claim 12 .  
     
     
       14. A method for the manufacture of a catalyst material, comprising: 
       powder coating, sputtering, plasma depositing or chemical coating the catalyst material according to  claim 1 ; wherein in said catalyst material M 1  and M 2  represent Co and Fe respectively.  
     
     
       15. A method for the manufacture of a catalyst material, comprising: 
       powder coating, sputtering, plasma depositing or chemical coating the catalyst material according to  claim 1 ; wherein in said catalyst material M 1  and M 2  represent Ni and Fe respectively.  
     
     
       16. A method for the generation of electrical power by using a fuel cell according to  claim 13 . 
     
     
       17. A CO tolerant low temperature fuel cell anode catalyst material having a surface, comprising: 
       a composition M x /Pt y /Sub;  
       wherein M is selected from the group consisting of elements Fe, Co, Rh and Ir; or  
       M represents M 1   m +M 2   n ;  
       M 1  and M 2  are different from each other, and are selected from the group of elements consisting of Fe, Co, Rh, Ir, Ni, Pd, Cu, Ag, Au and Sn;  
       Sub represents a substrate metal selected from the group consisting of Ru and Os which is present as an alloying metal in the surface anode material in an amount of less than 25% along with alloying metals M and Pt;  
       x is a number in the range of 0.7 to 1.3;  
       y is a number in the range of 0.7 to 2.3;  
       m and n are each a number in the range of 0.7 to 2.3; and  
       x, y, m and n signify the relative occurrence of the different elements at the surface, not including the substrate metal.  
     
     
       18. An anode for a fuel cell, comprising: 
       a Ru or Os metal substrate having a surface modified as a CO tolerant, low temperature fuel cell anode surface alloy catalyst in which the Ru or Os (Sub) metal forms an alloy composition with Pt and modifying element M and has the formula: M x /Pt y /Sub  
       wherein M is selected from the group consisting of elements Fe, Co, Rh and Ir; or  
       M represents M 1   m +M 2   n ; wherein M 1  and M 2  are different from each other, and are selected from the group of elements consisting of Fe, Co, Rh, Ir, Ni, Pd, Cu, Ag, Au and Sn;  
       the Sub metal is present in the surface alloy catalyst in an amount of less than 25%;  
       x is a number in the range of 0.7 to 1.3;  
       y is a number in the range of 0.7 to 2.3;  
       m and n are each a number in the range of 0.7 to 2.3; and  
       x, y, m and n signify the relative occurrence of the different elements at the surface, not including the substrate metal.  
     
     
       19. A method for the generation of electrical power, comprising: 
       operating a fuel cell whose anode is the anode catalyst material of  claim 1  in which hydrogen fuel is oxidized at the anode catalyst thereby generating electrical power.